Fabrication of a Disposable Amperometric Sensor for the Determination of Nitrite in Food

Abstract

Silver nanoparticles (AgNPs) were synthesized through an environmentally friendly method with tea extract as a reduction agent. By immobilizing them on the surface of a low-cost pencil graphite electrode (PGE) with the aid of a simple and well-controlled in-situ electropolymerization method, a novel nanosensing interface for nitrite was constructed. The film-modified PGE showed good electrocatalytic effects on the oxidation of nitrite and was characterized through scanning electron microscopy, X-ray photoelectron spectroscopy, and electrochemical techniques. Characterization results clearly show that the successful modification of AgNPs improved the surface area and conductivity of PGEs, which is beneficial to the high sensitivity and short response time of the nitrite sensor. Under the optimal detection conditions, the oxidation peak current of nitrite had a good linear relationship with its concentration in the range of 0.02–1160 μmol/L with a detection limit of 4 nmol/L and a response time of 2 s. Moreover, the sensor had high sensitivity, a wide linear range, a good anti-interference capability, and stability and reproducibility. Additionally, it can be used for the determination of nitrite in food.

Editors’ Choice—Review—Advances in Electrochemical Sensors: Improving Food Safety, Quality, and Traceability

“…The design of these sensors often incorporates advanced materials for electrode modification, such as carbon nanotubes or metal nanoparticles, to enhance surface area, electron transfer rates, and selectivity towards specific analytes, thereby improving the sensor's sensitivity and specificity for food safety applications. 13,14 Potentiometric sensors.-Potentiometric sensors operate based on the measurement of the potential difference between a working electrode and a reference electrode, with this potential being directly related to the logarithm of the ion activity in the sample, as described by the Nernst equation. These sensors are particularly suited for the detection of ions and pH levels in food products, providing crucial information for assessing food quality and safety.…”